Abstract: A light guide device for transmitting light through a column of light transmitting medium and into an adjacent culture growing solution, including a barrier structure for separating the medium and solution, the barrier structure being light transmissive to allow for extraction of light and being adapted to hold a material of reduced refractive index relative to the medium so as to provide total internal reflection for light incident the barrier structure at greater than a critical angle to thereby guide the light through the device.

Abstract: The present invention provides a method of fabricating a preform (10) for a microstructured optical fibre. The method includes providing at least one hole forming element (13) in a mold. Each hole forming element (13) is elongate and is composed of a polymeric material that stretches and reduces in thickness upon application of a tensile stress (such as a nylon line). The method also includes forming the preform material (12) around, and contiguous, with an external surface portion of each hole forming element (13). The method further includes applying a tensile stress to a portion (14) of each hole forming element (13) to locally thin a zone (18) of each hole forming element (13), the thinning resulting in local detachment of the zone (18) from the preform material (10). A length of the detached zone (18) increases while the tensile stress is applied leaving a tubular portion in the preform material (12) where the hole forming element (13) was attached.

Abstract: The invention relates to side-scattering light guides that generally comprise a core of transparent optically homogenous material seeded with diffuser particles. The light guide also comprises an optically transmitting sheath, having a lower refractive index than the core, surrounding and in contact with the sides of the core to prevent any light being transmitted along the core from escaping through the core's sides. In general, the diffuser particles impart only a small deviation to light rays incident upon them, and are distributed to scatter light being transmitted along the core so that at least some of the scattered light exits the sides of the core. A diffusing jacket is arranged to intercept scattered light exiting the sides of the core.

Abstract: The invention relates to a light emitting device consisting of one or more light sources coupled to a light guide containing diffuser particles having a refractive index close to the refractive index of the core of the light guide. The diffuser particles cause a scattering of the light emitted from the light sources so that light emitted from the light emitting device has colour variation imperceptible to the human eye and small and gradual variations in intensity.

Abstract: A side scattering light guide (10) for emitting light comprises a substantially transparent polymer core (12) surrounded by a transparent or translucent polymer cladding (14). The core (12) includes a light scattering additive (20) arranged to scatter light within the core so that at least some of the light passes through the cladding (14) to be emitted from the light guide (10). The light scattering additive (20) yields a high ratio of forward to backward scattering and is preferably in the form of diffuser particles. The type, density, concentration and/or refractive index of the light scattering additive may be selected to achieve the desired side scattering characteristics. A method of manufacturing the side scattering light guide (10) is also disclosed.

Abstract: An optical conduit (53) for transmitting and releasing luminescent radiation (61, 62, 63) emitted from a luminescent concentrator (51), the luminescent concentrator (51) and optical conduit (52) comprising an optical system which is adapted to release to an area to be illuminated the luminescent radiation which is otherwise trapped in the optical system by total internal reflection. The optical conduit (53) includes a luminaire (57), such as a plurality of scattering regions for scattering trapped light so that the scattered light acquires the angle of incidence required to released from the conduit (53). The scattering regions may be provided by shape irregularities on the surface of the conduit (53) or inhomogeneities within the conduit (53). The conduit (53) may consist of flexible overlaid light guides (65a, 65b and 65c) and a luminaire fitting (55) optically coupled thereto.

Abstract: A lighting system for an interior of a building and the like includes a stack (102) of fluorescent sheets for collecting and converting sunlight into concentrated light. The stack (102) is of a substantially rectangular prism shape having top and bottom surfaces, opposed side surfaces defining therebetween a width of the stack (102), and opposed end surfaces defining therebetween a length of the stack (102), wherein the length of the stack (102) is sufficiently greater than the width of the stack (102) such that its aspect ratio as herein defined is greater than 4.0. The lighting system also includes a flexible light guide (104) for channeling the concentrated light to a light emitting fitting for the interior of the building or the like. The light guide (104) is optically coupled by optical joint (103) with the stack (102) through one of the end surfaces of the stack (102).

Abstract: A lighting system for an interior of a building and the like includes a means (30) for collecting and converting sunlight into concentrated light. The collecting means (30) is optically coupled, preferably by way of optical joint (43), coupling means (44), and optical joint (45), to a channelling means (46), such as an optical cable, so that the concentrated light passes to the channelling means (46) and is channelled to a light emitting fitting for the interior of the building and the like.